1. Technical Field
The disclosure relates to a system and method (generally referred to as a “system”) for active noise cancellation, particularly applicable in a higher temperature environment.
2. Related Art
Engine order cancellation (EOC) is commonly used to reduce noise caused by harmonic disturbances generated by motors and engines such as combustion engines. EOC is a type of active noise control (ANC) that uses signals originating from the engines such as the revolutions per minute (RPM) signal as a reference to generate a sound wave that is opposite in phase to the engine vibration-induced noise. In addition, error microphones provide feedback on the amplitude and phase to refine noise-cancelling effects. The concept of EOC can also be applied in environments such as, for example, heating, ventilation and air conditioning (HVAC) environments or vehicle exhaust environments. Duct-like arrangements, as they may be used in the environments mentioned above, provide a good basis for the application of ANC including EOC to achieve an all encompassing noise reduction. However, these environments may also include obstacles to implementing ANC such as, e.g., high ambient temperatures, low ambient temperatures, humidity, moisture and chemically aggressive substances, and, thus, the requirements to the ANC systems operated in these environments are high. While sensor technology has made some progress, the performance of ANC in total when operated under harsh environmental conditions such as high temperatures is still not satisfactory.